15. Collections and Generics

Try these first

1. 1.

   What is a Collection in Java?

   Hint

   Consider grouping items together.

2. 2.

   Name one implementation of the List interface.

   Hint

   Think of a dynamic-sized collection.

3. 3.

   What does a List in Java allow?

   • Only unique elements
   • Duplicates and ordering
   • Only primitive types

   Hint

   Think about sequences and repetitions.

4. 4.

   True or False: A Set in Java can contain duplicate elements.

   • True
   • False

   Hint

   Consider the basic definition of a Set.

5. 5.

   Given a list of integers, write a Java method that returns a Set of unique values. Discuss its advantages based on your understanding of Sets.

   Hint

   Consider using HashSet's add() method.

6. 6.

   Create a generic method that reverses an array of any type. Show how generics improve the flexibility of your code.

   Hint

   Think about how the method should handle type parameters.